Another useful resource is the SPARQL 1.1 Evaluation Test Results which is the SPARQL working group document where they track implementations compliance with the SPARQL 1.1 standard based on reports submitted by vendors.
Currently it only lists a few but expect to see a lot more on there soon as once the recommendations enter Candidate/Proposed Recommendation stage the group must gather evidence of multiple interoperable implementations so you're likely to start seeing lots of vendors submitting their reports as they want to be able to point to an official document saying they support SPARQL 1.1
